Pasting long strings into the script parameters for Add 3D Function Surface?
I can't see any maxlen parameters in the script:

https://gitorious.org/blender-scripts/blender-3d-function-surface/source/add_mesh_3d_function_surface.py

And on Windows using Blender 2.70, I can store at least 1,000,000,000 characters in a StringProperty():

&gt;&gt;&gt; C.scene.p = "x"*1000000000
&gt;&gt;&gt; len(C.scene.p)
1000000000


The problem here is that there's a limit at layout level of 399 chars. You can actually type 400 and more letters into a text field, but you won't see the characters appear!

If you paste from clipboard, only the first 399 characters are taken. You can circumvent it by using python:


Go to Scripting screen
Call the XYZ Math Surface operator (parameter fields appear in Redo panel)
Create a new text datablock in the Text Editor
Add the following (substitute x_eq for the other equation fields):import bpybpy.context.active_operator.x_eq = ""
Place the cursor between the two "" quote marks and paste your formula
Click Run Script or hit AltP - it will assign the formula text to the operator's parameter field.
Click e.g. the handle of the U min property in the Redo to panel to force an update (it will not change the mesh based on the manually set equation automatically!). Don't activate any of the equation fields, it may truncate them again!